/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.naming.factory;

import org.apache.naming.EjbRef;

import javax.naming.*;
import javax.naming.spi.ObjectFactory;
import java.util.Hashtable;

/**
 * Object factory for EJBs.
 *
 * @author Remy Maucherat
 */

public class EjbFactory
		implements ObjectFactory {


	// ----------------------------------------------------------- Constructors


	// -------------------------------------------------------------- Constants


	// ----------------------------------------------------- Instance Variables


	// --------------------------------------------------------- Public Methods


	// -------------------------------------------------- ObjectFactory Methods

	/**
	 * Create a new EJB instance.
	 *
	 * @param obj The reference object describing the DataSource
	 */
	@Override
	public Object getObjectInstance(Object obj, Name name, Context nameCtx,
	                                Hashtable<?, ?> environment)
			throws Exception {

		if (obj instanceof EjbRef) {
			Reference ref = (Reference) obj;

			// If ejb-link has been specified, resolving the link using JNDI
			RefAddr linkRefAddr = ref.get(EjbRef.LINK);
			if (linkRefAddr != null) {
				// Retrieving the EJB link
				String ejbLink = linkRefAddr.getContent().toString();
				Object beanObj = (new InitialContext()).lookup(ejbLink);
				// Load home interface and checking if bean correctly
				// implements specified home interface
	            /*
                String homeClassName = ref.getClassName();
                try {
                    Class home = Class.forName(homeClassName);
                    if (home.isInstance(beanObj)) {
                        System.out.println("Bean of type " 
                                           + beanObj.getClass().getName() 
                                           + " implements home interface " 
                                           + home.getName());
                    } else {
                        System.out.println("Bean of type " 
                                           + beanObj.getClass().getName() 
                                           + " doesn't implement home interface " 
                                           + home.getName());
                        throw new NamingException
                            ("Bean of type " + beanObj.getClass().getName() 
                             + " doesn't implement home interface " 
                             + home.getName());
                    }
                } catch (ClassNotFoundException e) {
                    System.out.println("Couldn't load home interface "
                                       + homeClassName);
                }
                */
				return beanObj;
			}

			ObjectFactory factory = null;
			RefAddr factoryRefAddr = ref.get(Constants.FACTORY);
			if (factoryRefAddr != null) {
				// Using the specified factory
				String factoryClassName =
						factoryRefAddr.getContent().toString();
				// Loading factory
				ClassLoader tcl =
						Thread.currentThread().getContextClassLoader();
				Class<?> factoryClass = null;
				if (tcl != null) {
					try {
						factoryClass = tcl.loadClass(factoryClassName);
					} catch (ClassNotFoundException e) {
						NamingException ex = new NamingException
								("Could not load resource factory class");
						ex.initCause(e);
						throw ex;
					}
				} else {
					try {
						factoryClass = Class.forName(factoryClassName);
					} catch (ClassNotFoundException e) {
						NamingException ex = new NamingException
								("Could not load resource factory class");
						ex.initCause(e);
						throw ex;
					}
				}
				if (factoryClass != null) {
					try {
						factory = (ObjectFactory) factoryClass.newInstance();
					} catch (Throwable t) {
						NamingException ex = new NamingException
								("Could not load resource factory class");
						ex.initCause(t);
						throw ex;
					}
				}
			} else {
				String javaxEjbFactoryClassName =
						System.getProperty("javax.ejb.Factory",
								Constants.OPENEJB_EJB_FACTORY);
				try {
					factory = (ObjectFactory)
							Class.forName(javaxEjbFactoryClassName).newInstance();
				} catch (Throwable t) {
					if (t instanceof NamingException)
						throw (NamingException) t;
					NamingException ex = new NamingException
							("Could not create resource factory instance");
					ex.initCause(t);
					throw ex;
				}
			}

			if (factory != null) {
				return factory.getObjectInstance
						(obj, name, nameCtx, environment);
			} else {
				throw new NamingException
						("Cannot create resource instance");
			}

		}

		return null;

	}


}

